Peter, If you have a good relationship with your suppliers I am
sure that they will go out of their way to please you. They want
you back as a customer right? They can always resell what you are
returning. Everyone has a bad choice moment. I bought some rubies
once and they looked great until I left the building and saw them
in real light. My suppliers took them back no questions or fuss.
They want happy customers. This is why I am loyal to the same
suppliers. Of course, if you do this on a regular basis they may
not want you as a customer.

If you bought this stuff at the AGTA show (or from a member of
AGTA at another show) you will have some recourse. They are
obligated to disclose treatment of gemstones at the time of
purchase. In any event I would send a couple of pieces to GIA
for an opinion as I have never heard of moonstone being filled
before. That doesn’t mean it hasn’t been done but I stay on top
of this type of info most of the time and I can’t ever recall
having heard of moonstone fills.